Face in the News: Rick Perry, Tim Pawlenty and Antonio Villaraigosa

(CBS News) A few months ago they battled Mitt Romney in the Republican primary contest, but now, they're leading supporters of his campaign. This week on "Face the Nation," host Bob Schieffer caught up with Governor Rick Perry and Tim Pawlenty about their campaign involvement and vice presidential potential.

Former Minnesota Governor Tim Pawlenty, who is believed to be on Romney's short-list of vice president picks, said while it would be an honor, he could best serve as a volunteer and surrogate speaker instead.

"I have encouraged people who asked this question in the campaign to look at other prospects," Pawlenty said. "But obviously anybody who would be asked to serve in a position like that would be honored."

Pawlenty is an active Romney surrogate, recently accompanying the presumptive Republican nominee on a leg of his six state "Every Town Counts" bus tour.

Pawlenty also addressed recent criticisms of Romney's tax reform plan lacking details. "He hasn't put out a specific plan to eliminate any of the particular deductions within the tax code," he said. "But he has talked pretty specifically how he would reform, reduce, and slow down government spending overall, and that would help put the country on a pathway to a balanced budget."

Turning the tables, Pawlenty then attacked President Obama for a lack of specifics on Medicaid and Medicare reform. In a comical twist, Pawlenty even offered to mow Schieffer's lawn if he could pinpoint details on Obama's entitlement reform. Schieffer, however, turned down his proposal; he lives in an apartment.

Earlier in the show, Texas Governor Rick Perry compared the Fast and Furious gun-running scandal to the 1970's Watergate break-in that led to the resignation of President Richard Nixon. He said that Obama's assertion of executive privilege to withhold documents in the contempt case of Attorney General Eric Holder was "Nixonian" by nature.

"Now, you have a President who is using his executive privilege to keep that information from Congress. If that's not Nixonian, then I don't know what it is," Perry said.

"We've had over 300 Mexican nationals killed, directly attributable to this Fast and Furious operation, where they brought those guns into Mexico. A former Marine and a Border Patrol agent by the name of Brian Terry lost his life," Perry said. "With Watergate you had a second-rate burglary."

(To read more about Perry's opinions on the Fast and Furious scandal, check out The Atlantic Wire and CNN)

Los Angeles Mayor Antonio Villaraigosa appeared on the show to talk more about President Obama's immigration reform. As the co-chairman of the Obama re-election campaign, he said that Romney has "amnesia" in regards to his comments that the President waited until his re-election to concentrate on the issue.

"The fact is the president has done what we should do, and that is addressed the fact that these kids have been living here for most of their lives," Villaraigosa said.

When Schieffer asked Romney last week if he would repeal Mr. Obama's directive to halt deportation of millions of young illegal immigrants, Romney failed to provide a straight answer and said he would consider a long-term solution. "He wouldn't answer it," Villaraigosa said. "Everybody who has watched [Romney] over the last week knows this: He hasn't changed his core policy. He supports the self-deportation of eleven million people." (Watch Schieffer's interview with Romney here)